Networked multimedia system

ABSTRACT

Systems and methods are disclosed for providing downstream signals to a plurality of receiver networks. A receiver network (i.e., a networked multimedia system) includes a splitter/isolation module (SIM), a primary set-top terminal (STT), and at least one remote device. The remote devices communicate with the primary STT via the SIM over coaxial cable. Accordingly, the remote devices utilize some or all of the features including hardware and software that are included in the primary STT via the networked multimedia system.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] The present application incorporates by reference in its entiretyherein copending U.S. provisional application having serial no.:60/416,155, which was filed on Oct. 4, 2002, and U.S. provisionalapplication having serial no.: 60/424,269, which was filed on Nov. 6,2002. Also, the present application is a continuation-in-part ofcopending U.S. patent applications having Ser. Nos.: 10/263,160,10/263,449, and 10/263,270, which were filed on Oct. 2, 2002 and areassigned to a common assignee, the teachings of which are herebyincorporated by reference.

FIELD OF THE INVENTION

[0002] This invention relates in general to broadband communicationssystems, and more particularly, -to the field of set-top terminals and anetworked multimedia system.

DESCRIPTION OF THE RELATED ART

[0003] Broadband communications systems, such as satellite and cabletelevision systems, are now capable of providing many services inaddition to analog broadcast video. In implementing enhancedprogramming, the set-top terminal (STT), otherwise known as the set-topbox, has become an important computing device for accessing variousvideo services. In addition to supporting traditional analog broadcastvideo functionality, many STTs now also provide other functionality,such as, for example, an interactive program guide (IPG),video-on-demand (VOD), subscription video-on-demand (SVOD) andfunctionality traditionally associated with a conventional computer,such as e-mail. Recently new functionality has been added toconventional STTs—namely the ability to video record an incoming videostream in digitized form onto a mass storage device such as a hard dishdrive, and playback that recorded video as desired by the user. Thisfunctionality has become known as a “digital video recorder” (DVR) orpersonal video recorder (PVR) and is viewed as a superior alternative toconventional video tape recorders for capture and subsequent playback ofprogramming content.

[0004] An STT is typically connected to a communications network (e.g.,a cable or satellite television network) and includes hardware andsoftware necessary to provide various services and functionality.Preferably, some of the software executed by an STT is downloaded and/orupdated via the communications network. Each STT also typically includesa processor, communication components, and memory, and is connected to atelevision or other display device. While many conventional STTs arestand-alone devices that are externally connected to a television, anSTT and/or its functionality may be integrated into a television orother device, as will be appreciated by those of ordinary skill in theart.

[0005] An STT is typically connected to a television set and located atthe home of the cable or satellite system subscriber. Since the STT islocated in the subscriber's premises, it typically may be used by two ormore users (e.g., household members). Television has become so prevalentin the United States, however, that the typical household may have twoor more television sets, each television set requiring its own STT ifthe subscriber wishes to have access to enhanced functionality. However,STTs can be expensive and users may not be willing to purchaseadditional expensive STTs. This is particularly true of STTsincorporating PVR functionality since such devices require not only theaddition of a hard disk drive but also additional processing componentsand software.

[0006] Therefore, there exists a need for systems and methods foraddressing these and/or other problems associated with STTs.Specifically, there exists a need for systems and methods that allowmultiple subscribers operating discrete STTs within a subscriberpremises or other local area to have access to programming and contentreceived by and/or stored in another STT.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention can be better understood with reference to thefollowing drawings. The components in the drawings are not necessarilydrawn to scale, emphasis instead being placed upon clearly illustratingthe principles of the invention. In the drawings, like referencenumerals designate corresponding parts throughout the several views.

[0008]FIG. 1 is a simplified block diagram depicting a non-limitingexample of a conventional broadband communications system.

[0009]FIG. 2 is a block diagram illustrating one preferred embodiment ofa networked multimedia system (NMS) in accordance with the presentinvention.

[0010]FIG. 3 is a simplified, non-limiting block diagram illustratingselected components of a primary STT in accordance with one preferredembodiment of the present invention.

[0011]FIG. 4 illustrates an example of a graph of the frequencies of thedownstream broadband signals and the predetermined frequencies of theup-converted selected signals.

[0012]FIG. 5 is a simplified diagram of one preferred embodiment of aremote STT device.

[0013]FIG. 6 is a block diagram illustrating one preferred embodiment ofa QPSK transmitter that converts user input command signals into FSKsignals for transmission to the splitter/isolation module (SIM).

[0014]FIG. 7 illustrates generation of an FSK signal for input serialdata x(n)=[10010].

[0015]FIG. 8 illustrates a second embodiment of the present inventionfor transmitting reverse command signals as OOK signals over the coaxialcable to the SIM.

[0016]FIG. 9 illustrates a block diagram of a second embodiment of theSIM 210 comprising passive splitter/isolation components in accordancewith the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Preferred embodiments of the invention can be understood in thecontext of a broadband communications system and a local network. Note,however, that the invention may be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.For example, transmitted broadband signals include at least one ofvideo/audio, telephony, data, or Internet Protocol (IP) signals, to namebut a few. Furthermore, remote devices included in the broadbandcommunications system receiving the transmitted broadband signals mayinclude a remote set-top terminal, a television, a consumer electronicsdevice such as a DVD player/recorder, a computer, a personal digitalassistant (PDA), or other device. All examples given herein, therefore,are intended to be non-limiting and are provided in order to helpclarify the description of the invention.

[0018] The present invention is directed towards a networked multimediasystem (NMS) that is suitable for use in a broadband communicationssystem. The NMS is typically located within a subscriber premise. Itwill be appreciated, however, that the NMS can also be used in amulti-unit dwelling, business, school, hotel, or hospital, among others.Advantageously, the NMS allows the premise to be locally networked(i.e., home-networked). In accordance with the present invention aprimary set-top terminal (STT) typically receives and forwards broadbandmultimedia content signals (e.g., digital or analog cable televisionchannels (i.e., audio/video signals), IP signals, VOD signals, softwareapplication signals, administrative signals, etc.) throughout the localnetwork to a plurality of remote devices. Additionally, the remotedevices are each capable of requesting from the primary STT andseamlessly receiving, for example, a cable channel, a stored or recordedpresentation, a VOD movie, or the interactive program guide, just as ifthe remote devices were equipped with the primary STT functionality. Inother words, the remote devices may be simplified, less-costly versionsof the primary STT but are capable of utilizing, via the local network,some or all of the advanced hardware and software features, such asmemory, a mass storage device, or software applications, that areavailable in the primary STT. A broadband communications system that issuitable in implementing a preferred embodiment of the present inventionis described hereinbelow.

[0019] An Example of a Broadband Communications System

[0020]FIG. 1 is a simplified block diagram depicting a non-limitingexample of a conventional broadband communications system 100. In thisexample, the communications system 100 includes a headend 110 that iscoupled to a local network (LN) 101 via a communications network (CN)130. The CN 130 may be any network that is suitable for transmittingpreferably downstream and upstream broadband multimedia signals, such asaudio/video signals, IP signals, telephony signals, or data signals toname but a few. The CN 130 may be, for example, a hybrid fiber/coax(HFC) network, a fiber-to-the-home (FTTH) network, a satellite network,or a fixed wireless network (e.g., MMDS), among others.

[0021] The LN 101 includes a set-top terminal (STT) 105 that providesthe broadband signals to the remote devices 140-1 and 140-2, and,optionally, to additional remote devices including, for example, remotedevice 140-3. The STT 105 may be coupled to the remote devices eitherdirectly or via one or more other devices. It will be appreciated thatthe STT 105 may be a stand-alone unit or may be integrated into anotherdevice, such as, for example, a television or a computer. Additionally,the remote devices may be located in different rooms than where the STT105 is located. Further information regarding the LN 101 is provided incopending U.S. patent application Ser. Nos.: 10/263,160; 10/263,270; and10/263,449, which were filed on Oct. 2, 2002, the disclosure andteachings of which are hereby incorporated in their entirety byreference.

[0022] The headend 110 may include one or more server devices (notshown) for providing video, audio, and/or data signals to the STT 105via the CN 130. The headend 110 and the STT 105 cooperate to provide auser with a variety of services via the remote devices 140-i (e.g.,140-1, 140-2, and/or 140-3 ). The services may include, for example,analog or digital television services and channels, video-on-demand(VOD) services, and/or pay-per-view (PPV) services, among others. Eachbroadcast television channel typically provides a sequence of televisionpresentations corresponding to a television station (e.g., ABC, NBC,CBS, or FNN, to name a few) and is typically identified by a channelnumber (e.g., channel 2, channel 3, channel 4, etc.). Additionally, atelevision station (e.g., the Fox News Network) that is identified by acertain channel number (e.g., channel 84) to viewers served by a firstservice provider may be identified by another channel number (e.g.,channel 45) to viewers served by a second service provider.

[0023] A preferred embodiment of the present invention may beimplemented in addition to or replacement of the local network 101 ofFIG. 1. The present invention will now be described in detail.

[0024]FIG. 2 is a block diagram illustrating one preferred embodiment ofa networked multimedia system (NMS) 200 in accordance with the presentinvention. The NMS 200 includes a master or primary STT 205, asplitter/isolation module (SIM) 210, and a plurality of remote devices,e.g., 215-1, 215-2, 215-n. It is to be noted that while the embodimentof FIG. 2 illustrates an NMS having but two remote devices, theinvention is not so limited. Indeed, any number of such remote devicesmay be employed, consistent with the requirements and capabilities ofthe NMS, as described herein. Briefly, the SIM 210 receives downstreambroadband signals from, for example, the headend or satellite andsubsequently provides the downstream signals to the primary STT 205 orto both the primary STT 205 and any one or all of the plurality ofremote devices 215-n depending on the implementation. Upon command, theprimary STT 205 may also forward selected real-time downstream signalsor stored signals to one or all of the remote devices 215-n via the SIM210. More specifically, the plurality of remote devices 215-ncommunicates with the primary STT 205 by sending reverse control/commandsignals via coaxial cable 220, 221-n requesting stored presentations orreal-time signals. It will be appreciated that other wired mediums, suchas telephone lines or data cables, may be used so long as the transportformat accommodates the desired transmission medium. Advantageously, inaccordance with the present invention, the plurality of remote devices215-n have access to all of the primary STT's hardware and softwarefunctionality, along with receiving downstream signals directly from theheadend via the SIM 210. In this manner, the remote devices 215-n mayhave limited functionality, thereby decreasing the overall costs to theservice provider and the subscriber while offering advanced services toall of the remote devices that are networked.

[0025] Furthermore, the primary STT 205 may also directly providebroadband signals to a coupled local device 225, which may be, forexample, a television, computer, or PDA. It will be appreciated that theprimary STT 205 may transmit signals to and receive control signals fromthe local device 225 via wireless devices (e.g., RF or IR devices) or awired medium (e.g., coaxial cable, power lines, or telephone lines). Itwill also be appreciated that the primary STT 205 may be incorporated inthe local device 225. The primary STT 205 optionally includes, forexample, an IR receiver 368 (FIG. 3) for receiving user input controlsignals (e.g., signals indicating a channel change, IPG display, volumecontrol, or administrative signals) that are encoded in an IR signal.Those of ordinary skill in the art would understand elements andoperation of a typical IR receiver 368. Further information regardingthe transmitting and receiving of signals between the primary STT andthe coupled local device via wireless devices or a wired medium can befound in copending U.S. patent application Ser. No.: 10/008,581, theteachings of which are hereby incorporated by reference.

[0026] A Preferred Embodiment of the Primary STT 205

[0027]FIG. 3 is a simplified, non-limiting block diagram illustratingselected components of a primary STT 205 in accordance with onepreferred embodiment of the present invention. In other embodiments, aprimary STT 205 may include only some of the components shown in FIG. 3,in addition to other components that are not shown in FIG. 3. Theprimary STT 205 has electronic components (e.g., processor 305, memory310, etc.) that are coupled to a local interface 315, which can include,for example, one or more buses or other wired or wireless connections.The processor 305 is a hardware device for executing software,particularly that stored in memory 310. The processor 305 can be acustom-made or commercially available processor for executing softwareinstructions. When the primary STT 205 is in operation, the processor305 is configured to execute software stored within the memory 310, tocommunicate data to and from the memory 310, and to generally controloperations of the primary STT 205 according to the software.

[0028] The memory system 310 may include any one or combination ofvolatile memory elements (e.g., random access memory (RAM), dynamic RAM(DRAM), static RAM (SRAM), synchronous DRAM (SDRAM), magnetic RAM(MRAM), etc.) and nonvolatile memory elements (e.g., read only memory(ROM), hard drive, tape, compact disc ROM (CD-ROM), etc.). Moreover, thememory system 310 may incorporate electronic, magnetic, optical and/orother types of storage multimedia. Note that the memory system 310 canhave a distributed architecture, where various memory components aresituated remotely from one another, but can be accessed by the processor305.

[0029] The software in memory 310 may include one or more separateprograms, each of which comprises executable instructions forimplementing logical functions. In the example of FIG. 3, the softwarein memory 310 includes an operating system (OS) 320, a WatchTVapplication 321, a navigator application 322, a personal video recorder(PVR)/digital video recorder (DVR) application 323, a driver 324, a VODapplication 325, and an IPG application 326, among others. The OS 320controls the execution of other software and provides management andcontrol services including, for example, scheduling, input-outputcontrol, file and data management, memory management, and communicationcontrol. The WatchTV application 321 is used to help provide a user witha requested broadcast television channel. The EPG application 326provides an interactive program guide that mainly includes listings oftelevision channels provided by the primary STT 205, but may alsopresent additional services, such as an NMS interactive guide. Thenavigator application 322 is used to route user input commands torespective software applications that have registered with the navigatorapplication 322 to receive the respective commands. The VOD application325 provides a user with video-on-demand presentations, such as, forexample, movies that are selected via an on-screen movie catalog. ThePVR application 323 may provide user interface (UI) screens that can beused to manage (e.g., record, playback, and delete) the content of astorage device 330. Accordingly, the PVR application 323 may record ordelete data from the storage device 330 with the help of a softwaredriver 324, which controls read and write operations performed on thestorage device 330. In one preferred embodiment, the storage device 330includes a hard drive that reads from and writes to a hard disk. It willbe appreciated that other software applications may be included inmemory 310.

[0030] A tuner system 335 includes, in one implementation, anout-of-band tuner (not shown) for receiving out-of-band signals (e.g.,administrative signals that were modulated using quadrature phase shiftkeying (QPSK)), and a plurality of in-band tuners 340-n (e.g.,quadrature amplitude modulation (QAM)/analog tuners) for receivinganalog and/or digital in-band television channels. Alternatively, thetuner system 335 may only include one in-band tuner depending on adesired implementation. A signal processing system 345 may be capable ofdemodulating, demultiplexing, decrypting, and decoding signals that aretuned to by the tuner system 335. Although shown as one module, thesignal processing system may comprise multiple modules that are locatedin different parts of the primary STT 205. It will be appreciated thatin the preferred embodiment of the present invention the number oftuners 340-n typically corresponds to at least the optional coupledlocal device(s) 225 and the storage device 330. Further informationregarding adding additional tuners can be found in copending U.S. patentapplication Ser. No. 10/263,449, which was filed on Oct. 2, 2002, theteachings of which are hereby incorporated by reference.

[0031] The primary STT 205 also includes an upstream transmitter 350 anda local transmitter 355. The upstream transmitter 350, which mayalternatively be included in the tuner system 335, preferably includes aQPSK/QAM modulator (not shown) that is used to transmit the upstreamdata to the CN 130 (FIG. 1). The local transmitter 355 preferablyincludes a UHF (ultra high frequency) modulator for modulating, forexample, a television channel that is output to the local device 255(FIG. 2) through an optional interface 365, such as for example anEthernet wireless device, depending on a desired implementation.

[0032] The primary STT 205 may also include an IR receiver 368, a remotedevice command receiver 285, and/or an RF receiver 375, which detectrespective signals (IR, electric, or wireless RF) having encoded remotecontrol commands requesting television services, channels, or other NMSservices. In one embodiment, the remote device command receiver 285 mayforward received remote control signals from the plurality of remotedevices 215-n to the processor 305, which then, for example, routes thecommands to respective applications for processing.

[0033] An output system 380 may be used to encode television servicesthat are to be output to, for example, local device 225 (FIG. 2), whichmay be a television or computer, via the connection 111. The outputsystem 380 may provide a television 225 with signals that are in, forexample, NTSC (National Television Standard Committee) format. Inanother embodiment, if the television 225 is a digital television, forexample, a high definition television (HDTV), then the output system mayinclude an MPEG (Motion Picture Expert Group) encoder for encodingtelevision service signals in an MPEG-2 format. It will be appreciatedthat the primary STT 205 may also provide multimedia content signals toother remote devices (e.g., a computer, a remote set-top terminal, or aPDA) located in the network, such as illustrated in FIG. 1.

[0034] Referring to FIG. 2 in conjunction with FIG. 3, the primary STT205 receives via the SIM 210 downstream broadband signals (i.e., signalsthat are typically in the range from 45 MHz to 870 MHz). A low passfilter in diplex filter 235 provides the downstream signals to the tunersystem 335 and the remote device command receiver 285. Upon command fromthe processor 305, the tuner system 335 may send the downstream signalsto any local devices 225, the storage device 330 for optional storage,and additionally to a modulator 240. More specifically, the processor305 instructs the tuner system 335 to extract specified content signalsfrom the downstream signals. By way of example, a tuner 340 responsiveto the coupled local device 225 provides selected content signalsdirectly to the local device 225. The tuner 340 or a plurality of tuners340-n that are responsive to a remote device 215-n via the processor 305may forward selected real-time presentations directly to the modulator240 for transmission to the plurality of remote devices 215-n.Furthermore, upon user input from the primary STT 205 or any one of theremote devices 215-n, the processor 305 may instruct the tuner system335 to provide content presentations to the storage device 330 forstorage. The stored presentations are subsequently available forforwarding to any of the remote devices 215-n and/or the local device255 upon instruction from the processor 305. User input signals will bediscussed in further detail hereinbelow relating with a preferredembodiment of the remote devices 215-n.

[0035] In accordance with the present invention, the modulator 240modulates the selected content signals (i.e., NMS presentations)provided from either the tuner system 335 or the storage device 330prior to forwarding to the SIM 210. For example, a preferred embodimentof the present invention uses a QAM modulator, which may be used foreffectively transmitting signals over coaxial cable in a cabletelevision environment. Other embodiments may include a QPSK modulatorin a satellite environment, an 8VSB (8-vestigial sideband) modulator ina digital terrestrial environment in the U.S., and a COFDM (codedorthogonal frequency division multiplexing) modulator in a digitalterrestrial environment in Europe, or alternatively an analog modulator.The modulator 240 converts the signals to a predetermined intermediatefrequency. Subsequently, the modulated presentations are up-converted toa predetermined higher frequency that is preferably greater than thehighest frequency used in the system with, for example, a UHF converter245. FIG. 4 illustrates an example of a graph of the conventionalfrequencies of the downstream broadband signals 403 and thepredetermined frequencies of the up-converted NMS presentations 405. Apreferred embodiment of the present invention is to up-convert the NMSpresentations to an available high frequency channel, for example,channel 134, which may have a frequency range from 852 MHz to 858 MHz.The service provider, therefore, would provide downstream signals in therange from 45 MHz to approximately 840 MHz, thereby leaving frequenciesgreater than 840 MHz available for the transmission of NMSpresentations. Accordingly, the NMS presentations 405 do not interferewith the downstream signals that may be concurrently provided via thecommon coax 220, 221-n to the primary STT 205 and the remote devices215-n. It will be appreciated that other frequency ranges can be usedthat are either in-band (e.g., from 45 MHz to 860 MHz) or out-of-band(e.g., from 865 MHz to 1 GHz) so long as the predetermined frequencyrange is not used for transmission of the downstream signals or iswithin the range that is tunable by the plurality of remote devices215-n. The up-converted NMS presentations are subsequently provided tothe SIM 210 via a high pass filter in the diplex filter 235.

[0036] Furthermore, the remote device command receiver 285 is includedin the primary STT 205 for receiving reverse NMS command signals fromthe plurality of remote devices 215-n. Command signals will be discussedfurther hereinbelow; however, the command signals can be transmitted inthe form of on-off keying (OOK) signals, frequency shift keying (FSK)signals, or serial data transmissions, among others. The remote devicecommand receiver 285, therefore, includes the respective demodulator,such as an OOK demodulator or an FSK demodulator that demodulates thesignals as known to one skilled in the art.

[0037] Additionally, an optional DC source 280, which may supply, forexample, 12 to 15 volts (V) and 200 milliamps (mA), may be provided topower an amplifier 275 located the SIM 210, if necessary. If required,the amplifier 275 amplifies the downstream signals received from the CN130. It will be appreciated that if the SIM 210 is a passivesplitter/isolation module, the DC source 280 is not necessary.

[0038] Preferred Embodiments of the SIM 210

[0039] Referring again to FIG. 2, the selected NMS presentations areprovided by the primary STT 205 to the SIM 210 via the coaxial cable220. In a first embodiment of the lo SIM 210, the selected NMSpresentations are routed to the plurality of remote devices 215-n via adiplex filter 250. A splitter 266 provides the NMS presentations to HPF255, which subsequently provides the filtered NMS presentations tosplitter 267, diplex filter 260, and splitter 265. The high pass filter(HPF) 255 has low attenuation at the frequencies of the NMS presentationand high isolation at lower frequencies, and thus, provides highisolation between port 268 and ports 269-n at these lower frequencies.It will be appreciated that a bandpass filter (BPF) can alternatively beused depending on the transmission frequencies of the NMS presentations.Splitter 265 provides the NMS presentations to the plurality of remotedevices 215-n. It will be appreciated that, at the frequencies of theNMS presentations, splitters 266 and 267 provide low insertion lossbetween port 268 and the splitter 265, thereby ensuring the NMSpresentations are routed to the plurality of remote devices 215-n.Additionally, in an active SIM 210, the amplifier 275 further preventsthe NMS presentations from reaching the CN 130.

[0040] Moreover, diplex filters 250 and 270 provide a path for upstreamsignals from the primary STT 205 to the headend. Similarly, diplexfilters 260 and 270 provide a path for upstream signals from theplurality of remote devices 215-n to the headend. A high pass filter 271allows any upstream signals (e.g., signals ranging from 5 MHz to 45 MHz)to pass through to the diplex filter 270 on to the CN 130. It will beappreciated that the reverse signals intended to remain in the NMS 200,such as reverse command signals from the remote devices 215-n, arereflected back and routed to the primary STT 205. Furthermore, the SIM210 receives the downstream broadband signals from the headend 110 atdiplex filter 270, which provides the downstream signals to the primarySTT 205 or, alternatively, to both the primary STT 205 and the pluralityof remote devices 215-n.

[0041]FIG. 9 illustrates a block diagram of a second embodiment of a SIM210 comprising passive splitter/isolation components in accordance withthe present invention. More specifically, the NMS presentations from theprimary STT 205 are provided to SIM 210 via port 268. A band rejectfilter (BRF) 910 rejects the frequencies of the selected NMSpresentations (e.g., from 852 MHz to 858 MHz), thereby not allowing thepresentations to leave the network 200. It will be appreciated that theNMS presentations are reflected off the BRF 910 and routed to thesplitter 265 for transmission to the plurality of remote devices 215-n.It will be appreciated that there is a high insertion loss between a SIMport 269-n and the primary STT input port 268 at all other frequencies.A high pass filter (HPF) 915 is included to ensure that the reversecommand signals provided by the plurality of remote devices 215-n arereflected and routed to the primary STT 205 and not transmitted to theCN 130.

[0042] Notably, the preferred embodiments of the SIM 210 provideprotection against any of the reverse command signals from leaving theNMS 200, thereby ensuring proper delivery to the primary STT 205 whilealso avoiding any interference with separate networked multimediasystems that may be in close proximity. A further advantage is that theSIM 210 enhances privacy and security by making the NMS 200 unobservableto any upstream devices in the CN 130.

[0043] A Preferred Embodiment of a Remote Device 215-n

[0044]FIG. 5 is a simplified diagram of one preferred embodiment of aremote STT device 215-n. It will be appreciated that the remote devices215-n may be identical to the primary STT 205 and just share the storagedevice contents of the primary STT 205. Alternatively, the remotedevices 215-n may be a simplified or conventional version of the primarySTT 205. A processor 305 and a tuner system 335, which may be asimplified processor and only one tuner, may be included to extractchannels from the received downstream broadband signals. Additionally,decryptors and decoders (not shown) may be included to decode encodedsignals for proper processing and display. Furthermore, the remotedevices 215-n may or may not include memory. Preferably, the remotedevices 215-n include a user input receiver 368, such as an IR receiveror an RF receiver, that receives signals from a remote control, such asan IR remote control or an RF remote control. It will be appreciatedthat the remote control 505 is not required, and any user input devicecould be incorporated in the remote devices 215-n.

[0045] As mentioned, the reverse command signals, which typicallyoriginate from user input signals (e.g., tuned channels, NMS functions,or IPG display) or generated administrative signals (e.g., turn-onsignals), could be processed using various methods depending upon thetype of remote control used. By way of example, if an RF remote controlis used, the RF signals could be modulated to a desired frequency thatdoes not interfere with any downstream or upstream signals that aretransmitted via the common coaxial cable 221-n. There may be, however,RF interference issues between the remote control and other RF devicesin the area. Alternatively, if an IR remote control device is used, RFinterference is not an issue. The IR signals do, however, requiremodulation with a carrier frequency and subsequently multiplexed ontothe coaxial cable 221-n. Accordingly, this will prevent the requirementof running separate reverse command transmission media to accommodatethe serial data streams, such as twisted pair cable, from each remotedevice 215-n to the SIM 210. It will be appreciated that if the userinput signals indicate non-NMS signals, for example, a channel change orvolume change, the remote device 215-n processes and performs theoperation internally. In other words, these types of user input signalsare not routed throughout the NMS 200.

[0046] Notably, in accordance with the present invention, the reversecommand signals are transmitted via the coaxial cable 221-n that isrouted between each remote device 215-n and the SIM 210. A preferredembodiment of the present invention processes and transmits the reversecommand signals that are indicative of user input commands usingfrequency shift keying (FSK) and utilizes existing components that aretypically included in a conventional remote set-top terminal. Asmentioned, a QPSK modulator is typically included in the upstreamtransmitter 350 for modulating conventional upstream signals, which aresignals ranging from 5 MHz to 40 MHz, for transmission to the headendand, in accordance with the present invention, for modulating thereverse command signals that are routed throughout the NMS 200.Preferably, the existing QPSK modulator modulates the reverse commandsignals to an FSK signal at a frequency that is below the conventionalupstream signals (i.e., below 5 MHz). In this manner, the reversecommand signals do not interfere with conventionally transmittedupstream signals that may be provided from the remote devices 215-n.

[0047]FIG. 6 is a block diagram illustrating one preferred embodiment ofa QPSK transmitter 600 that converts user input command signals into FSKsignals for transmission to the SIM 210. The user input command signals,such as a channel change, request for an IPG display, request for astored presentation, etc., are presented from the user input receiver368 to the QPSK transmitter 600 as serial data. In conventional QPSKtransmitters, the input serial data is converted to parallel signals (A,B), and the parallel signals are subsequently mapped directly to a phasechange A(p by a differential encoder. An example is shown in Table 1.TABLE 1 Input Serial Data A B Δφ 0 0 0 0 1 +π/2 1 0 −π/2 1 1 π

[0048] The output of the conventional QPSK transmitter is, therefore, aQPSK modulated output signal. Disadvantageously, however, the receivingequipment, such as would be required in the primary STT 205, is complexand expensive. On the other hand, the present invention includes aprecoder 605 that precodes the input serial data to generate a frequencyshift keyed signal, thereby requiring a less complex, inexpensivereceiver in the primary STT 205.

[0049] In accordance with the present invention, the precoder 605operates on the input serial data to produce, for example, 2 symbols foreach input bit. By way of example, the input serial data, x(n), may bechanged to output serial data, x′(n), as follows:

when x(n)=1: x′(n)=[01 01]; and

when x(n)=0: x′(n)=[10 10],

[0050] where the sample time of the input x is, in this example, 4 timesthat of the output x′. For x(n)=1, therefore, the precoder 605 generatestwo symbols with each symbol producing a phase change of +π/2 (as shownin Table 1), and a total phase change of π. Similarly, for x(n) =0, theprecoder 605 generates two symbols with each symbol producing a phasechange of −π/2, and a total phase change of −π. It will be appreciatedthat the output serial data, x′(n), may be any arbitrary number ofsymbols, such as four symbols for an input bit, and the phase changesmay be different than shown in Table 1 so long as the change issignificant enough that the FSK demodulator in the command receiver 285in the primary STT 205 can detect the change in frequency. Additionally,the precoder 605 does not have to be a dedicated piece of hardware; theprecoder 605 can be used elsewhere within the remote terminal 215-n.Furthermore, the precoder 605 can be, for example, a look-up table thatis stored in memory, or it can be hardware, such as logic gates. Theprecoded signals are provided to a serial-to-parallel (S/P) converter610 for providing parallel signals (A, B). A differential encoder 615receives the A and B bits and encodes them according to the phasechanges shown in the example Table 1 to provide mapped I and Q bits. Anoptional filter 620 may be used to shape the I/Q pulse. A carrierfrequency is modulated by the I and Q bits via a QPSK modulator 625 toprovide the FSK output signals at a desired frequency, such as, forexample, in the range from 2 MHz to 4.5 MHz.

[0051] It will be appreciated that the QPSK transmitter 600 may beenabled only when there are reverse command signals being transmitted,thereby enabling a way of preventing collisions between remote devices215-n. Further embodiments of collision avoidance will be discussedfurther below. Additionally, the remote command signals may be encryptedand, therefore, decrypted accordingly in the command receiver 285.Further information regarding encryption/decryption can be found incopending U.S. patent application Ser. No. 10/154,495, which was filedon May 24, 2002 and is assigned to a common assignee, the teachings ofwhich are hereby incorporated by reference.

[0052]FIG. 7 illustrates generation of an FSK signal for input serialdata x(n)=[10010]. Graph 7(a) illustrates the phase vs. the time overthe duration of each symbol, which is shown to be linear, however, thisis not required. As per the previous example, x(1)=[01 01], whichcorresponds to a total phase change of +π. The next input serial bit,x(0), is converted to [10 10], which corresponds to a total phase changeof −π. Similarly, the next input serial bit, x(0), corresponds to atotal phase change of −π, and so forth. As can be seen, graph 7(b)illustrates a single positive value when x(n)=1, and a single negativevalue when x(n)=0. This constitutes the FSK signal. Note that, since thephase of the signal is continuous, the FSK signal generated may bedesignated as a continuous-phase FSK signal (CPFSK). It will beappreciated that there are further embodiments of an FSK transmitter. Byway of example, an FSK transmitter could include a direct digitalfrequency synthesizer with two selectable frequency words.

[0053]FIG. 8 illustrates a second embodiment of the present inventionfor transmitting reverse command signals as OOK signals over the coaxialcable 221-n to the SIM 210. An on-off keying (OOK) inserter device 805is either internally or externally added to the conventional remotedevice 215 for producing a modulated serial data stream that is suitablefor transmission over coaxial cable. A logic gate 810 receives theserial data stream, which is indicative of the user input commandsignals, and an oscillator 815 provides an oscillated input signal at aspecified frequency, such as 2 MHz. The logic gate 810 essentially gatesthe serial data stream to provide a modulated signal according to theuser input signals for transmission over the coaxial cable 221-n.

[0054] Referring again to FIG. 2, the reverse command signals from eachof the plurality of remote devices 215-n are provided to the primary STT205 via the diplex filters 260, 250 in the SIM 210. The remote devicecommand receiver 285 receives the reverse command signals and instructsthe primary STT 205 to provide return NMS presentations accordingly. Apreferred embodiment of the command receiver 285 includes an FSKdemodulator. It will be appreciated, however, that the receiver 285 caninclude any demodulator that is in accordance with the reverse commandsignal transmission technique.

[0055] After processing, the command receiver 285 sends signalsindicative of the reverse command signal to the processor 305. By way ofexample, if a remote device 215-n requests the latest IPG or a list ofthe stored presentations, the processor 305 accesses the IPG display orthe list via the navigational interface 322, which subsequently forwardsthe IPG or the list to the requesting remote device 215-n. The remotedevice 215-n may then, upon user input, select a presentation from theIPG or the stored presentations. For example, upon receipt of thereverse command signals indicative of a selected stored presentation,the processor 305 extracts the selected presentation from the storagedevice 330 and transmits the presentation to the remote device 215-n viathe modulator 240. The remote device 215-n tunes to the modulatorfrequency and waits for the response (i.e., the stored presentation).Notably, in accordance with the present invention a remote device 215-nthat views a stored presentation is capable of utilizing advancedfeatures via the primary STT 205, such as play, pause, fast-forward, orrewind functions, with the selected presentation. More specifically, aremote device 215-n receives user input indicating one of the play,pause, fast-forward, or rewind signals and forwards the reverse commandsignals indicative of the user input signals to the primary STT 205. Theprocessor 305 subsequently performs the function relating to the userinput signals on the stored presentation that is being viewed, such as,for example, pausing transmission of the stored presentation untilfurther commands are received.

[0056] A further example is a remote device 215-n that requests avideo-on-demand (VOD) presentation from a headend server via the primarySTT 205. It will be appreciated that if the remote device 215-n is abroadcast-only device, it is incapable of transmitting upstream signalsto the headend. In this case and in accordance with the presentinvention, the broadcast-only device 215-n may transmit reverse commandsignals to the primary STT 205, which acts as a gateway device.Subsequent to processing the command signals, the primary STT 205 maytransmit upstream signals that are indicative of the command signals tothe headend server. For instance, the remote device 215-n selects apresentation from a displayed VOD list and transmits the reverse commandsignals to the primary STT 205. The primary STT 205 processes thesignals and subsequently transmits upstream signals to the headendserver requesting the particular VOD presentation. The VOD presentationis then transmitted along with the downstream signals to the primary STT205, which may optionally store the presentation on the storage device330, and, either concurrently or subsequently, forward the VODpresentation to the requesting broadcast-only remote device 215-n.Alternatively, the requesting remote device 215-n can extract the VODpresentation with an included tuner from the downstream signals using,for example, a predetermined channel frequency or other identifyingconvention.

[0057] Collision avoidance between the remote devices 215-n can besignificantly improved in several ways. A preferred embodiment of thepresent invention, however, utilizes the asynchronous input data bits asan inexpensive way to transmit the reverse command signals from theplurality of remote devices 215-n to the primary STT 205. Morespecifically, the user input data is a sequence of asynchronouscharacters called a cell. Each cell contains a preamble, which isfollowed by several characters. The characters include, for example,,onestart bit, eight data bits, and one stop bit. An example may be that alow logical level represents a start bit or a data bit 0; a high logicallevel represents a stop bit or data bit 1. The eight data bits are thereverse command signals. After modulation by the QPSK transmitter 600,the FSK asynchronous signals are provided to the primary STT 205. Ademodulator (not shown) included in the command receiver 285 demodulatesthe signals and provides the demodulated signals to a universalasynchronous receiver/transmitter (UART) (not shown) for framing intodata bytes using the asynchronous characters. Advantageously, by usingthe asynchronous data, the command receiver 285 does not need time tosynchronize with a remote device's reference clock. It will beappreciated that other collision avoidance and collision recoverymethods exist and can replace or further enhance the above-describedembodiment of the present invention. These methods are known to oneskilled in the art.

[0058] It should be emphasized that the above-described embodiments ofthe invention are merely possible examples, among others, of theimplementations, setting forth a clear understanding of the principlesof the invention. Many variations and modifications may be made to theabove-described embodiments of the invention without departingsubstantially from the principles of the invention. All suchmodifications and variations are intended to be included herein withinthe scope of the disclosure and invention and protected by the followingclaims. In addition, the scope of the invention includes embodying thefunctionality of the preferred embodiments of the invention in logicembodied in hardware and/or software-configured mediums.

What is claimed is:
 1. A network system, comprising: a primary set-topterminal (STT) for receiving downstream signals from a communicationsnetwork and for selectively storing presentations included in thedownstream signals, the primary STT comprising: a tuner system forproviding tuned signals; a modulator for modulating the tuned signals toa predetermined frequency and for providing modulated signals; and aplurality of remote devices coupled to the primary STT, each remotedevice for receiving the downstream signals and for selecting andreceiving a tuned modulated signal, wherein the tuner system isresponsive to a processor, and wherein the processor is responsive toone of the plurality of remote devices.
 2. The network system of claim1, wherein the primary STT further includes a storage device for storingthe presentations, and wherein the tuned modulated signal includes astored presentation.
 3. The network system of claim 1, wherein themodulator is one of a QAM modulator, a QPSK modulator, a 8 VSBmodulator, and a COFDM modulator.
 4. The network system of claim 1,further comprising a splitter/isolation module (SIM) for receiving thedownstream signals and for providing the downstream signals to at leastone of the primary STT and the plurality of remote devices, and forreceiving upstream signals from at least one of the primary STT and theplurality of remote devices and providing the upstream signals to thecommunications network.
 5. The network system of claim 4, wherein theSIM receives the tuned modulated signal and provides the tuned modulatedsignal to the plurality of remote devices, and wherein the SIM receivesat least one reverse command signal provided by the plurality of remotedevices and provides the at least one reverse command signal to theprimary STT.
 6. The network system of claim 5, wherein the upstreamsignals are transmitted in a plurality of upstream frequencies, andwherein a reverse frequency of the at least one reverse command signalis excluded from the plurality of upstream frequencies.
 7. The networksystem of claim 1, wherein each of the plurality of remote devicescommunicates with the primary STT by transmitting at least one reversecommand signal via coaxial cable.
 8. The network system of claim 7,wherein the at least one reverse command signal is transmitted in an OOKformat.
 9. The network system of claim 7, wherein the at least onereverse command signal is transmitted in an FSK format.
 10. The networksystem of claim 9, wherein a QPSK transmitter transmits the at least onereverse command signal in the FSK format, the QPSK transmittercomprises: a precoder for precoding the at least one reverse commandsignal, a serial-to-parallel converter for providing a parallel precodedsignal, an encoder for encoding the parallel precoded signal into I andQ bits, and a QPSK modulator for modulating the I and Q bits into theFSK format.
 11. The network system of claim 1, wherein the downstreamsignals are transmitted in a plurality of downstream frequencies, andwherein the predetermined frequency of the tuned modulated signal isexcluded from the plurality of downstream frequencies.
 12. The networksystem of claim 1, wherein the tuned modulated signal is one of a storedpresentation, a VOD presentation, an IPG application, an NMSapplication, and a television channel.
 13. The network system of claim1, wherein a remote device includes at least one tuner for tuning to apresentation included in the downstream signals.
 14. A broadbandcommunications system for transmitting downstream signals having adownstream frequency range and upstream signals having an upstreamfrequency range, the broadband communications system including aheadend, a communications network, and a plurality of receiver networks,a receiver network comprising: a splitter/isolation module (SIM) havingan input port and a plurality of output ports, the SIN for receivingdownstream signals at the input port and for outputting the downstreamsignals to at least one of the plurality of output ports, and forreceiving at the plurality of output ports a plurality of upstreamsignals and for outputting the plurality of upstream signals at theinput port; a primary set-top terminal (STT) coupled to one of theplurality of output ports for receiving the downstream signals, and forproviding one of the plurality of upstream signals, the primary STTincluding a tuner system for providing at least one tuned presentation;and at least one remote device coupled to another of the plurality ofoutput ports, the at least one remote device in communication with theprimary STT, the at least one remote device for receiving the downstreamsignals, the at least one remote device for selecting and receiving theat least one tuned presentation.
 15. The broadband communications systemof claim 14, the receiver network further including a local devicecoupled to the primary STT for receiving the tuned presentation, whereinthe local device provides the tuned presentation to a viewing display.16. The broadband communications system of claim 14, the primary STTfurther including a modulator coupled to the tuner system, the modulatorfor modulating the at least one tuned presentation to a predeterminedfrequency.
 17. The broadband communications system of claim 16, whereinthe primary STT further includes a storage device for storing the atleast one tuned presentation.
 18. The broadband communications system ofclaim 17, wherein the storage device, upon command from a processor,provides a stored presentation to the modulator for modulation andtransmission to the at least one remote device.
 19. The broadbandcommunications system of claim 18, wherein the at least one remotedevice can perform, via the primary STT, play, pause, fast-forward,rewind, and stop functions on the received stored presentation.
 20. Thebroadband communication system of claim 16, wherein the predeterminedfrequency is excluded from the downstream frequency range.
 21. Thebroadband communications system of claim 14, wherein the at least oneremote device provides reverse command signals having a reversefrequency requesting the tuned presentation, and wherein the reversefrequency is excluded from the upstream frequency range.
 22. Thebroadband communications system of claim 17, wherein the primary STTfurther includes a processor for controlling the tuner system and thestorage device.
 23. A method for providing a networked multimedia systemcomprising the steps of: receiving downstream signals having adownstream frequency range at a primary STT and a plurality of remotedevices; providing the downstream signals via a tuning system located inthe primary STT to at least one of a coupled local device, a storagedevice, and a modulator; receiving a reverse command signal having areverse frequency at the primary STT provided by at least one of theplurality of remote devices; processing the reverse command signal andextracting a presentation indicative of the reverse command signal fromone of the downstream signals and the storage device; modulating theextracted presentation to a modulation frequency; and transmitting themodulated presentation to the at least one of the plurality of remotedevices.
 24. The method of claim 23, further comprising the step ofproviding upstream signals having an upstream frequency range to aheadend via a communications network provided by the primary STT,wherein the reverse frequency of the reverse command signal is excludedfrom the upstream frequency range.
 25. The method of claim 24, whereinthe modulation frequency is excluded from the downstream frequencyrange.
 26. The method of claim 23, wherein the reverse command signal istransmitted in an FSK format.
 27. The method of claim 23, wherein thereverse command signal is transmitted in an OOK format.
 28. A method forproviding a networked multimedia system, the networked multimedia systemincluding a primary STT, a splitter/isolation module (SIM), and aplurality of remote devices, the method comprising the steps of: at atleast one of the plurality of remote devices, receiving user inputsignals that are indicative of a selected presentation; processing theuser input signals to determine whether the selected presentation isindicative of one of a downstream signal and a stored presentation; andtransmitting the user input signals that are indicative of the storedpresentation to the primary STT via the SIM; and at the primary STT,processing the user input signals; extracting the stored presentation;modulating the extracted stored presentation to a predeterminedfrequency; and transmitting the stored presentation to the at least oneof the plurality of remote devices.
 29. The method of claim 28, furthercomprising the steps of: at the primary STT, receiving the downstreamsignal; and storing presentations included in the downstream signal in astorage device.
 30. A method for providing an interactive network, theinteractive network including a headend facility for transmitting andreceiving interactive signals over a communications network to a networkmultimedia system, the network multimedia system including a gatewaydevice, a splitter/isolation module (SIM), and a plurality of clientdevices, the method comprising the steps of: at at least one of theplurality of client devices, receiving user input signals that areindicative of a selected presentation; processing the user input signalsto determine whether the selected presentation is indicative of one of abroadcast content, a stored presentation, and a headend serverpresentation; and transmitting reverse command signals indicative of oneof the stored presentation and the headend server presentation to thegateway device via the SIM; at the gateway device, processing thereverse command signals to determine whether the selected presentationis one of the stored presentation and the headend server presentation;and transmitting the processed headend server presentation to theheadend facility via the communications network; and at the headendfacility, processing and extracting the content presentation that isindicative of the headend server presentation; and forwarding thecontent presentation to the at least one of the plurality of clientdevices.
 31. The method of claim 30, further comprising the steps of:subsequent to determining the selected presentation is the storedpresentation, extracting the stored presentation from a storage device;modulating the stored presentation at a predetermined frequency; andtransmitting the modulated stored presentation to the plurality ofclient devices via the SIM.
 32. The method of claim 30, furthercomprising the steps of: at the gateway device, receiving the broadcastcontent; upon input, tuning a selected presentation included in thebroadcast content; and providing the tuned presentation to one of alocal device, a storage device, and a modulator.